Over the past two decades in Taiwan, the incidence of breast cancer is increasing. The equivalent peak of Taiwanese occurred about 10 years younger that United States. Younger than 45 years old female (pre-menopause) breast cancer women were increasing rapidly in Taiwan. But, gene line mutation of Asian-Pacific countries, such as China, Taiwan, Korea, Japan and Malaysia occurred significant lower than Caucasian women with breast cancer. Chemical hormone replacement therapy that may cause breast cancer is not as popular in Taiwan as in Western countries. To explain this by epidemiology,we found Taiwanese women with premenstrual or post menstruation problems are greatly interest to use traditional Chinese herbs or herbal estrogen. It is reasonable to suspect the overuse of herbs may contribute to the Taiwanese breast cancer incidence. Breast MRI image for detecting breast lesions is extremely sensitive. It can identify breast cancer at early stage of the formation. In this book,we introduce our experiences on how MRI helps to alert women with overuse hormone or herb to increase their breast cancer risk. We also discuss the benefit of using anti-estrogen to prevent breast cancer.